Deuterated 5,6-dihydro-1h-pyridin-2-one compounds

ABSTRACT

The invention is directed to deuterated 5,6-dihydro-1H-pyridin-2-one compounds and pharmaceutical compositions containing such compounds that are useful in treating infections by hepatitis C virus.

FIELD OF THE INVENTION

The invention is directed to deuterated 5,6-dihydro-1H-pyridin-2-onecompounds and pharmaceutical compositions containing such compounds thatare useful in treating infections by hepatitis C virus.

BACKGROUND OF THE INVENTION

Hepatitis C is a major health problem world-wide. The World HealthOrganization estimates that 170 million people are chronic carriers ofthe hepatitis C virus (HCV), with 4 million carriers in the UnitedStates alone. In the United States, HCV infection accounts for 40% ofchronic liver disease and HCV disease is the most common cause for livertransplantation. HCV infection leads to a chronic infection and about70% of persons infected will develop chronic histological changes in theliver (chronic hepatitis) with a 10-40% risk of cirrhosis and anestimated 4% lifetime risk of hepatocellular carcinoma. The CDCestimates that each year in the United States there are 35,000 new casesof HCV infection and approximately ten thousand deaths attributed to HCVdisease.

The current standard of care is a pegylated interferon/ribavirincombination at a cost of approximately $30,000/year. These drugs havedifficult dosing problems and side-effects and do not achieve asustained virological response in a significant number of diagnosedpatients. Pegylated interferon treatment is associated with menacingflu-like symptoms, irritability, inability to concentrate, suicidalideation, and leukocytopenia. Ribavirin is associated with hemolyticanemia and birth defects.

The overall response to this standard therapy is low; as approximatelyone third of patients do not respond. Of those who do respond, somerelapse within six months of completing 6-12 months of therapy. As aconsequence, the long-term response rate for all patients enteringtreatment is only about 50%. The relatively low response rate and thesignificant side-effects of current therapy anti-HCV drug treatments,coupled with the negative long term effects of chronic HCV infection,result in a continuing medical need for improved therapy. Antiviralpharmaceuticals to treat RNA virus diseases like HCV are few, and asdescribed above are often associated with multiple adverse effects.

A number of publications have described NS5B inhibitors useful in thetreatment of hepatitis C infection. See, e.g., U.S. Patent ApplicationPublication No. US 2008/0031852 (describing [1,2-b]pyridazinonecompounds); U.S. Patent Application Publication No. US 2006/0189602(disclosing certain pyridazinones); U.S. Patent Application PublicationNo. US 2006/0252785 (disclosing selected heterocyclics); andInternational Publication Nos. WO 03/059356, WO 02/098424, and WO01/85172 (each describing a particular class of substitutedthiadiazines).

While there are, in some cases, medicines available to reduce diseasesymptoms, there are few drugs to effectively inhibit replication of theunderlying virus. The significance and prevalence of RNA virus diseases,including but not limited to chronic infection by the hepatitis C virus,and coupled with the limited availability and effectiveness of currentantiviral pharmaceuticals, have created a compelling and continuing needfor new pharmaceuticals to treat these diseases.

SUMMARY OF THE INVENTION

The present invention describes deuterated 5,6-dihydro-1H-pyridin-2-onecompounds and pharmaceutically acceptable salts thereof, which areuseful in treating or preventing a hepatitis C virus infection in apatient in need thereof comprising administering to the patient atherapeutically or prophylactically effective amount of a deuterated5,6-dihydro-1H-pyridin-2-one compound.

In a general aspect, the invention relates to compounds of Formula I

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷,R¹⁸, R¹⁹, R²⁰, R²¹, R²², and R²³ are independently selected fromhydrogen and deuterium, and

R⁹ is F,

wherein at least one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R¹⁰, R¹¹, R¹²,R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², and R²³ is deuterium,or a pharmaceutically acceptable salt, hydrate, solvate, tautomer orstereoisomer thereof.

In one aspect of the invention at least one of the R², R³, or R⁴substituents is deuterium, wherein the remaining R substituents arehydrogen.

In one aspect of the invention at least one of the R¹² or R¹³substituents is deuterium, wherein the remaining R substituents arehydrogen.

In one aspect of the invention at least one of the R⁷, R⁸, R¹⁰, R¹¹,R¹², R¹³ substituents is deuterium, wherein the remaining R substituentsare hydrogen.

In one aspect of the invention R¹⁶ or R¹⁷ is deuterium and R¹⁸ or R¹⁹ isdeuterium, wherein the remaining R substituents are hydrogen.

In one aspect of the invention at least one of R⁷, R⁸, R¹⁰, R¹¹, R¹⁶ orR¹⁷ is deuterium and R¹⁸ or R¹⁹ is deuterium, wherein the remaining Rsubstituents are hydrogen.

In one aspect of the invention at least one of R¹², R¹³, R¹⁶ or R¹⁷ isdeuterium and R¹⁸ or R¹⁹ is deuterium, wherein the remaining Rsubstituents are hydrogen.

In one aspect of the invention at least one of R⁷, R⁸, R¹⁰, R¹¹, R¹²,R¹³, R¹⁶ or R¹⁷ is deuterium and R¹⁸ or R¹⁹ is deuterium, wherein theremaining R substituents are hydrogen.

In one aspect of the invention at least one of R², R³, R⁴, R¹² and R¹³substituents are deuterium, wherein the remaining R substituents arehydrogen.

In one aspect of the invention at least one of R², R³, R⁴, R⁷, R⁸, R¹⁰,R¹¹, R¹² and R¹³ substituents are deuterium, wherein the remaining Rsubstituents are hydrogen.

In one aspect of the invention at least one of R², R³, R⁴, R¹⁶ or R¹⁷ isdeuterium and R¹⁸ or R¹⁹ is deuterium, wherein the remaining Rsubstituents are hydrogen.

In one aspect of the invention at least one of R², R³, R⁴, R⁷, R⁸, R¹⁰,R¹¹, R¹², R¹³, R¹⁶ or R¹⁷ is deuterium and R¹⁸ or R¹⁹ is deuterium,wherein the remaining R substituents are hydrogen.

The invention is also directed to pharmaceutically acceptable salts andpharmaceutically acceptable solvates of the compounds of Formula I.Advantageous methods of making the compounds of Formula I are alsodescribed.

In one aspect, the invention encompasses a method for treating orpreventing hepatitis C virus infection in a mammal in need thereof,preferably in a human in need thereof, comprising administering to thepatient a therapeutically or prophylactically effective amount of aFormula I compound. In one embodiment, the invention encompasses amethod for treating or preventing hepatitis C virus infection byadministering to a patient in need thereof a therapeutically orprophylactically effective amount of a Formula I compound that is aninhibitor of HCV NS5B polymerase.

In another aspect, the invention encompasses a method for treating orpreventing hepatitis C virus infection in a patient in need thereof,comprising administering to the patient a therapeutically orprophylactically effective amount of a compound of Formula I and apharmaceutically acceptable excipient, carrier, or vehicle.

In another aspect, the invention encompasses a method for treating orpreventing hepatitis C virus infection in a patient in need thereof,comprising administering to the patient a therapeutically orprophylactically effective amount of a compound of Formula I and anadditional therapeutic agent, preferably an additional antiviral agentor an immunomodulatory agent.

DETAILED DESCRIPTION OF THE INVENTION

Where the following terms are used in this specification, they are usedas defined below:

The terms “comprising,” “having” and “including” are used herein intheir open, non-limiting sense.

The term “alkyl”, as used herein, unless otherwise indicated, includesC₁-C₁₂ saturated monovalent hydrocarbon radicals having straight,branched, or cyclic moieties (including fused and bridged bicyclic andspirocyclic moieties), or a combination of the foregoing moieties. Foran alkyl group to have cyclic moieties, the group must have at leastthree carbon atoms.

The term “immunomodulator” refers to natural or synthetic productscapable of modifying the normal or aberrant immune system throughstimulation or suppression.

The term “preventing” refers to the ability of a compound or compositionof the invention to prevent a disease identified herein in patientsdiagnosed as having the disease or who are at risk of developing suchdisease. The term also encompasses preventing further progression of thedisease in patients who are already suffering from or have symptoms ofsuch disease.

The term “patient” or “subject” means an animal (e.g., cow, horse,sheep, pig, chicken, turkey, quail, cat, dog, mouse, rat, rabbit, guineapig, etc.) or a mammal, including chimeric and transgenic animals andmammals. In the treatment or prevention of HCV infection, the term“patient” or “subject” preferably means a monkey or a human, mostpreferably a human. In a specific embodiment the patient or subject isinfected by or exposed to the hepatitis C virus. In certain embodiments,the patient is a human infant (age 0-2), child (age 2-17), adolescent(age 12-17), adult (age 18 and up) or geriatric (age 70 and up) patient.In addition, the patient includes immunocompromised patients such as HIVpositive patients, cancer patients, patients undergoing immunotherapy orchemotherapy. In a particular embodiment, the patient is a healthyindividual, i.e., not displaying symptoms of other viral infections.

The term a “therapeutically effective amount” refers to an amount of thecompound of the invention sufficient to provide a benefit in thetreatment or prevention of viral disease, to delay or minimize symptomsassociated with viral infection or viral-induced disease, or to cure orameliorate the disease or infection or cause thereof. In particular, atherapeutically effective amount means an amount sufficient to provide atherapeutic benefit in vivo. Used in connection with an amount of acompound of the invention, the term preferably encompasses a non-toxicamount that improves overall therapy, reduces or avoids symptoms orcauses of disease, or enhances the therapeutic efficacy of or synergieswith another therapeutic agent.

The term a “prophylactically effective amount” refers to an amount of acompound of the invention or other active ingredient sufficient toresult in the prevention of infection, recurrence or spread of viralinfection. A prophylactically effective amount may refer to an amountsufficient to prevent initial infection or the recurrence or spread ofthe infection or a disease associated with the infection. Used inconnection with an amount of a compound of the invention, the termpreferably encompasses a non-toxic amount that improves overallprophylaxis or enhances the prophylactic efficacy of or synergies withanother prophylactic or therapeutic agent.

The term “in combination” refers to the use of more than oneprophylactic and/or therapeutic agents simultaneously or sequentiallyand in a manner that their respective effects are additive orsynergistic.

The term “treating” refers to:

(i) preventing a disease, disorder, or condition from occurring in ananimal that may be predisposed to the disease, disorder and/orcondition, but has not yet been diagnosed as having it;

(ii) inhibiting the disease, disorder, or condition, i.e., arresting itsdevelopment; and

(iii) relieving the disease, disorder, or condition, i.e., causingregression of the disease, disorder, and/or condition.

The terms “R” and “S” indicate the specific stereochemical configurationof a substituent at an asymmetric carbon atom in a chemical structure asdrawn.

The term “rac” indicates that a compound is a racemate, which is definedas an equimolar mixture of a pair of enantiomers. A “rac” compound doesnot exhibit optical activity. The chemical name or formula of a racemateis distinguished from those of the enantiomers by the prefix (±)- orrac- (or racem-) or by the symbols RS and SR.

The terms “endo” and “exo” are descriptors of the relative orientationof substituents attached to non-bridgehead atoms in abicyclo[x.y.z]alkane (x≧y>z>0).

The terms “syn” and “anti” are descriptors of the relative orientationof substituents attached to bridgehead atoms in a bicyclo[x.y.z]alkane(x≧y>z>0).

The term “exo” is given to a substituent (e.g., Br attached to C-2 inthe example below) that is orientated towards the highest numberedbridge (z bridge, e.g., C-7 in example below); if the substituent isorientated away from the highest numbered bridge it is given thedescription “endo”.

The term “syn” is given to a substituent attached to the highestnumbered bridge (z bridge, e.g., F attached to C-7 in the example below)and is orientated towards the lowest numbered bridge (x bridge, e.g.,C-2 and C-3 in example below); if the substituent is orientated awayfrom the lowest numbered bridge it is given the description “anti.”

The terms “cis” and “trans” are descriptors which show the relationshipbetween two ligands attached to separate atoms that are connected by adouble bond or are contained in a ring. The two ligands are said to belocated cis to each other if they lie on the same side of a plane. Ifthey are on opposite sides, their relative position is described astrans. The appropriate reference plane of a double bond is perpendicularto that of the relevant o-bonds and passes through the double bond. Fora ring it is the mean plane of the ring(s).

The term “deuterium enrichment” refers to the percentage ofincorporation of deuterium at a given position in a molecule in theplace of hydrogen. For example, deuterium enrichment of 1% at a givenposition means that 1% of molecules in a given sample contain deuteriumat the specified position. Because the naturally occurring distributionof deuterium is about 0.0156%, deuterium enrichment at any position in acompound synthesized using non-enriched starting material is about0.0156%. The deuterium enrichment can be determined using conventionalanalytical methods known to one of ordinary skill in the art, includingmass spectrometry and nuclear magnetic resonance spectroscopy.

The term “is/are deuterium,” when used to describe a given position in amolecule such as R¹-R²³ or the symbol “D,” when used to represent agiven position in a drawing of a molecular structure, means that thespecified position is enriched with deuterium above the naturallyoccurring distribution of deuterium. In an embodiment deuteriumenrichment is of no less than about 25%, in another no less than about50%, in another no less than about 75%, or in another no less than about95% of deuterium at the specified position.

The compounds of the invention may exhibit the phenomenon oftautomerism. While Formula I cannot expressly depict all possibletautomeric forms, it is to be understood that Formula I is intended torepresent any tautomeric form of the depicted compound and is not to belimited merely to a specific compound form depicted by the formuladrawings.

Some of the inventive compounds may exist as single stereoisomers (i.e.,essentially free of other stereoisomers), racemates, and/or mixtures ofenantiomers and/or diastereomers. All such single stereoisomers,racemates and mixtures thereof are intended to be within the scope ofthe present invention. Preferably, the inventive compounds that areoptically active are used in optically pure form.

As generally understood by those skilled in the art, an optically purecompound having one chiral center (i.e., one asymmetric carbon atom) isone that consists essentially of one of the two possible enantiomers(i.e., is enantiomerically pure), and an optically pure compound havingmore than one chiral center is one that is both diastereomerically pureand enantiomerically pure. Preferably, the compounds of the presentinvention are used in a form that is at least 90% free of otherenantiomers or diastereomers of the compounds, that is, a form thatcontains at least 90% of a single isomer (80% enantiomeric excess(“e.e.”) or diastereomeric excess (“d.e.”)), more preferably at least95% (90% e.e. or d.e.), even more preferably at least 97.5% (95% e.e. ord.e.), and most preferably at least 99% (98% e.e. or d.e.).

Additionally, Formula I is intended to cover solvated as well asunsolvated forms of the identified structures. For example, Formula Iincludes compounds of the indicated structure in both hydrated andnon-hydrated forms. Other examples of solvates include the structures incombination with isopropanol, ethanol, methanol, DMSO, ethyl acetate,pentyl acetate, acetic acid, or ethanolamine.

In addition to compounds of Formula I, the invention includespharmaceutically acceptable prodrugs, pharmaceutically activemetabolites, and pharmaceutically acceptable salts of such compounds andmetabolites.

“A pharmaceutically acceptable prodrug” is a compound that may beconverted under physiological conditions or by solvolysis to thespecified compound or to a pharmaceutically acceptable salt of suchcompound prior to exhibiting its pharmacological effect (s). Typically,the prodrug is formulated with the objective(s) of improved chemicalstability, improved patient acceptance and compliance, improvedbioavailability, prolonged duration of action, improved organselectivity, improved formulation (e.g., increased hydrosolubility),and/or decreased side effects (e.g., toxicity). The prodrug can bereadily prepared from the compounds of Formula I using methods known inthe art, such as those described by Burger's Medicinal Chemistry andDrug Chemistry, 1, 172-178, 949-982 (1995). See also Bertolini et al.,J. Med. Chem., 40, 2011-2016 (1997); Shan, et al., J. Pharm. Sci., 86(7), 765-767; Bagshawe, Drug Dev. Res., 34, 220-230 (1995); Bodor,Advances in Drug Res., 13, 224-331 (1984); Bundgaard, Design of Prodrugs(Elsevier Press 1985); Larsen, Design and Application of Prodrugs, DrugDesign and Development (Krogsgaard-Larsen et al., eds., Harwood AcademicPublishers, 1991); Dear et al., J. Chromatogr. B, 748, 281-293 (2000);Spraul et al., J. Pharmaceutical & Biomedical Analysis, 10, 601-605(1992); and Prox et al., Xenobiol., 3, 103-112 (1992).

“A pharmaceutically active metabolite” is intended to mean apharmacologically active product produced through metabolism in the bodyof a specified compound or salt thereof. After entry into the body, mostdrugs are substrates for chemical reactions that may change theirphysical properties and biologic effects. These metabolic conversions,which usually affect the polarity of the Formula I compounds, alter theway in which drugs are distributed in and excreted from the body.However, in some cases, metabolism of a drug is required for therapeuticeffect. For example, anticancer drugs of the anti-metabolite class mustbe converted to their active forms after they have been transported intoa cancer cell.

Since most drugs undergo metabolic transformation of some kind, thebiochemical reactions that play a role in drug metabolism may benumerous and diverse. The main site of drug metabolism is the liver,although other tissues may also participate.

A feature characteristic of many of these transformations is that themetabolic products, or “metabolites,” are more polar than the parentdrugs, although a polar drug does sometime yield a less polar product.Substances with high lipid/water partition coefficients, which passeasily across membranes, also diffuse back readily from tubular urinethrough the renal tubular cells into the plasma. Thus, such substancestend to have a low renal clearance and a long persistence in the body.If a drug is metabolized to a more polar compound, one with a lowerpartition coefficient, its tubular reabsorption will be greatly reduced.Moreover, the specific secretory mechanisms for anions and cations inthe proximal renal tubules and in the parenchymal liver cells operateupon highly polar substances.

As a specific example, phenacetin (acetophenetidin) and acetanilide areboth mild analgesic and antipyretic agents, but are transformed withinthe body to a more polar and more effective metabolite,p-hydroxyacetanilid (acetaminophen), which is widely used today. When adose of acetanilide is given to a person, the successive metabolitespeak and decay in the plasma sequentially. During the first hour,acetanilide is the principal plasma component. In the second hour, asthe acetanilide level falls, the metabolite acetaminophen concentrationreaches a peak. Finally, after a few hours, the principal plasmacomponent is a further metabolite that is inert and can be excreted fromthe body. Thus, the plasma concentrations of one or more metabolites, aswell as the drug itself, can be pharmacologically important.

“A pharmaceutically acceptable salt” is intended to mean a salt thatretains the biological effectiveness of the free acids and bases of thespecified compound and that is not biologically or otherwiseundesirable. A compound of the invention may possess a sufficientlyacidic, a sufficiently basic, or both functional groups, and accordinglyreact with any of a number of inorganic or organic bases, and inorganicand organic acids, to form a pharmaceutically acceptable salt. Exemplarypharmaceutically acceptable salts include those salts prepared byreaction of the compounds of the present invention with a mineral ororganic acid or an inorganic base, such as salts including sulfates,pyrosulfates, bisulfates, sulfites, bisulfites, phosphates,monohydrogenphosphates, dihydrogenphosphates, metaphosphates,pyrophosphates, chlorides, bromides, iodides, acetates, propionates,decanoates, caprylates, acrylates, formates, isobutyrates, caproates,heptanoates, propiolates, oxalates, malonates, succinates, suberates,sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates,benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates,hydroxybenzoates, methoxybenzoates, phthalates, sulfonates,xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates,citrates, lactates, γ-hydroxybutyrates, glycolates, tartrates,methane-sulfonates, propanesulfonates, naphthalene-1-sulfonates,naphthalene-2-sulfonates, and mandelates.

If the inventive compound is a base, the desired pharmaceuticallyacceptable salt may be prepared by any suitable method available in theart, for example, treatment of the free base with an inorganic acid,such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid and the like, or with an organic acid, such as aceticacid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonicacid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, apyranosidyl acid, such as glucuronic acid or galacturonic acid, anα-hydroxy acid, such as citric acid or tartaric acid, an amino acid,such as aspartic acid or glutamic acid, an aromatic acid, such asbenzoic acid or cinnamic acid, a sulfonic acid, such asp-toluenesulfonic acid or ethanesulfonic acid, or the like.

If the inventive compound is an acid, the desired pharmaceuticallyacceptable salt may be prepared by any suitable method, for example,treatment of the free acid with an inorganic or organic base, such as anamine (primary, secondary or tertiary), an alkali metal hydroxide oralkaline earth metal hydroxide, or the like. Illustrative examples ofsuitable salts include organic salts derived from amino acids, such asglycine and arginine, ammonia, primary, secondary, and tertiary amines,and cyclic amines, such as piperidine, morpholine and piperazine, andinorganic salts derived from sodium, calcium, potassium, magnesium,manganese, iron, copper, zinc, aluminum and lithium.

In the case of agents that are solids, it is understood by those skilledin the art that the inventive compounds and salts may exist in differentcrystal, co-crystal, or polymorphic forms, all of which are intended tobe within the scope of the present invention and specified formulas.

Methods of Treatment and Prevention of Hepatitis C Viral Infections

The present invention provides methods for treating or preventing ahepatitis C virus infection in a patient in need thereof.

The present invention further provides methods for introducing atherapeutically effective amount of the Formula I compound orcombination of such compounds into the blood stream of a patient in thetreatment and/or prevention of hepatitis C viral infections.

The magnitude of a prophylactic or therapeutic dose of a Formula Icompound of the invention or a pharmaceutically acceptable salt,solvate, or hydrate, thereof in the acute or chronic treatment orprevention of an infection will vary, however, with the nature andseverity of the infection, and the route by which the active ingredientis administered. The dose, and in some cases the dose frequency, willalso vary according to the infection to be treated, the age, bodyweight, and response of the individual patient. Suitable dosing regimenscan be readily selected by those skilled in the art with dueconsideration of such factors.

The methods of the present invention are particularly well suited forhuman patients. In particular, the methods and doses of the presentinvention can be useful for immunocompromised patients including, butnot limited to cancer patients, HIV infected patients, and patients withan immunodegenerative disease. Furthermore, the methods can be usefulfor immunocompromised patients currently in a state of remission. Themethods and doses of the present invention are also useful for patientsundergoing other antiviral treatments. The prevention methods of thepresent invention are particularly useful for patients at risk of viralinfection. These patients include, but are not limited to health careworkers, e.g., doctors, nurses, hospice care givers; military personnel;teachers; childcare workers; patients traveling to, or living in,foreign locales, in particular third world locales including social aidworkers, missionaries, and foreign diplomats. Finally, the methods andcompositions include the treatment of refractory patients or patientsresistant to treatment such as resistance to reverse transcriptaseinhibitors, protease inhibitors, etc.

Doses

Toxicity and efficacy of the compounds of the invention can bedetermined by standard pharmaceutical procedures in cell cultures orexperimental animals, e.g., for determining the LD₅₀ (the dose lethal to50% of the population) and the ED₅₀ (the dose therapeutically effectivein 50% of the population). The dose ratio between toxic and therapeuticeffects is the therapeutic index and it can be expressed as the ratioLD₅₀/ED₅₀.

The data obtained from the cell culture assays and animal studies can beused in formulating a range of dosage of the compounds for use inhumans. The dosage of such compounds lies preferably within a range ofcirculating concentrations that include the ED₅₀ with little or notoxicity. The dosage may vary within this range depending upon thedosage form employed and the route of administration utilized. For anycompound used in the method of the invention, the therapeuticallyeffective dose can be estimated initially from cell culture assays. Adose may be formulated in animal models to achieve a circulating plasmaconcentration range that includes the IC₅₀ (i.e., the concentration ofthe test compound that achieves a half-maximal inhibition of symptoms)as determined in cell culture; alternatively, the dose of the Formula Icompound may be formulated in animal models to achieve a circulatingplasma concentration range of the compound that corresponds to theconcentration required to achieve a fixed magnitude of response. Suchinformation can be used to more accurately determine useful doses inhumans. Levels in plasma may be measured, for example, by highperformance liquid chromatography.

The protocols and compositions of the invention are preferably tested invitro, and then in vivo, for the desired therapeutic or prophylacticactivity, prior to use in humans. For example, in vitro assays which canbe used to determine whether administration of a specific therapeuticprotocol is indicated, include in vitro cell culture assays in whichcells that are responsive to the effects of the Formula I compounds areexposed to the ligand and the magnitude of response is measured by anappropriate technique. The assessment of the Formula I compound is thenevaluated with respect to the Formula I compound potency, and the degreeof conversion of the Formula I compound prodrug. Compounds for use inmethods of the invention can be tested in suitable animal model systemsprior to testing in humans, including but not limited to in rats, mice,chicken, cows, monkeys, rabbits, hamsters, etc. The compounds can thenbe used in the appropriate clinical trials.

The magnitude of a prophylactic or therapeutic dose of a prodrug of aFormula I compound of the invention or a pharmaceutically acceptablesalt, solvate, or hydrate thereof in the acute or chronic treatment orprevention of an infection or condition will vary with the nature andseverity of the infection, and the route by which the active ingredientis administered. The dose, and perhaps the dose frequency, will alsovary according to the infection to be treated, the age, body weight, andresponse of the individual patient. Suitable dosing regimens can bereadily selected by those skilled in the art with due consideration ofsuch factors. In one embodiment, the dose administered depends upon thespecific compound to be used, and the weight and condition of thepatient. Also, the dose may differ for various particular Formula Icompounds; suitable doses can be predicted on the basis of theaforementioned in vitro measurements and on the basis of animal studies,such that smaller doses will be suitable for those Formula I compoundsthat show effectiveness at lower concentrations than other Formula Icompounds when measured in the systems described or referenced herein.In general, the dose per day is in the range of from about 0.001 to 100mg/kg, preferably about 1 to 25 mg/kg, more preferably about 5 to 15mg/kg. For treatment of humans infected by hepatitis C viruses, about0.1 mg to about 15 g per day is administered in about one to fourdivisions a day, preferably 100 mg to 12 g per day, more preferably from100 mg to 8000 mg per day.

Additionally, the recommended daily dose ran can be administered incycles as single agents or in combination with other therapeutic agents.In one embodiment, the daily dose is administered in a single dose or inequally divided doses. In a related embodiment, the recommended dailydose can be administered once time per week, two times per week, threetimes per week, four times per week or five times per week.

In one embodiment, the compounds of the invention are administered toprovide systemic distribution of the compound within the patient. In arelated embodiment, the compounds of the invention are administered toproduce a systemic effect in the body.

In another embodiment the compounds of the invention are administeredvia oral, mucosal (including sublingual, buccal, rectal, nasal, orvaginal), parenteral (including subcutaneous, intramuscular, bolusinjection, intraarterial, or intravenous), transdermal, or topicaladministration. In a specific embodiment the compounds of the inventionare administered via mucosal (including sublingual, buccal, rectal,nasal, or vaginal), parenteral (including subcutaneous, intramuscular,bolus injection, intraarterial, or intravenous), transdermal, or topicaladministration. In a further specific embodiment, the compounds of theinvention are administered via oral administration. In a furtherspecific embodiment, the compounds of the invention are not administeredvia oral administration.

Different therapeutically effective amounts may be applicable fordifferent infections, as will be readily known by those of ordinaryskill in the art. Similarly, amounts sufficient to treat or prevent suchinfections, but insufficient to cause, or sufficient to reduce, adverseeffects associated with conventional therapies are also encompassed bythe above described dosage amounts and dose frequency schedules.

Combination Therapy

Specific methods of the invention further comprise the administration ofan additional therapeutic agent (i.e., a therapeutic agent other than acompound of the invention). In certain embodiments of the presentinvention, the compounds of the invention can be used in combinationwith at least one other therapeutic agent. Therapeutic agents include,but are not limited to antibiotics, antiemetic agents, antidepressants,and antifungal agents, anti-inflammatory agents, antiviral agents,anticancer agents, immunomodulatory agents, α-interferons,β-interferons, ribavirin, alkylating agents, hormones, cytokines, ortoll-like receptor modulators. In one embodiment the inventionencompasses the administration of an additional therapeutic agent thatis HCV specific or demonstrates anti-HCV activity.

The Formula I compounds of the invention can be administered orformulated in combination with antibiotics. For example, they can beformulated with a macrolide (e.g., tobramycin (Tobi®)), a cephalosporin(e.g., cephalexin (Keflex®), cephradine (Velosef®), cefuroxime(Ceftin®), cefprozil (Cefzil®), cefaclor (Ceclor®), cefixime (Suprax®)or cefadroxil (Duricef®)), a clarithromycin (e.g., clarithromycin(Biaxin®)), an erythromycin (e.g., erythromycin (EMycin®)), a penicillin(e.g., penicillin V (V-Cillin K® or Pen Vee K®)) or a quinolone (e.g.,ofloxacin (Floxin®), ciprofloxacin (Cipro®) or norfloxacin (Noroxin®)),aminoglycoside antibiotics (e.g., apramycin, arbekacin, bambermycins,butirosin, dibekacin, neomycin, neomycin, undecylenate, netilmicin,paromomycin, ribostamycin, sisomicin, and spectinomycin), amphenicolantibiotics (e.g., azidamfenicol, chloramphenicol, florfenicol, andthiamphenicol), ansamycin antibiotics (e.g., rifamide and rifampin),carbacephems (e.g., loracarbef), carbapenems (e.g., biapenem andimipenem), cephalosporins (e.g., cefaclor, cefadroxil, cefamandole,cefatrizine, cefazedone, cefozopran, cefpimizole, cefpiramide, andcefpirome), cephamycins (e.g., cefbuperazone, cefmetazole, andcefminox), monobactams (e.g., aztreonam, carumonam, and tigemonam),oxacephems (e.g., flomoxef, and moxalactam), penicillins (e.g.,amdinocillin, amdinocillin pivoxil, amoxicillin, bacampicillin,benzylpenicillinic acid, benzylpenicillin sodium, epicillin,fenbenicillin, floxacillin, penamccillin, penethamate hydriodide,penicillin o-benethamine, penicillin 0, penicillin V, penicillin Vbenzathine, penicillin V hydrabamine, penimepicycline, andphencihicillin potassium), lincosamides (e.g., clindamycin, andlincomycin), amphomycin, bacitracin, capreomycin, colistin, enduracidin,enviomycin, tetracyclines (e.g., apicycline, chlortetracycline,clomocycline, and demeclocycline), 2,4-diaminopyrimidines (e.g.,brodimoprim), nitrofurans (e.g., furaltadone, and furazolium chloride),quinolones and analogs thereof (e.g., cinoxacin, clinafloxacin,flumequine, and grepagloxacin), sulfonamides (e.g., acetylsulfamethoxypyrazine, benzylsulfamide, noprylsulfamide,phthalylsulfacetamide, sulfachrysoidine, and sulfacytine), sulfones(e.g., diathymosulfone, glucosulfone sodium, and solasulfone),cycloserine, mupirocin and tuberin.

The Formula I compounds of the invention can also be administered orformulated in combination with an antiemetic agent. Suitable antiemeticagents include, but are not limited to, metoclopromide, domperidone,prochlorperazine, promethazine, chlorpromazine, trimethobenzamide,ondansetron, granisetron, hydroxyzine, acetylleucine monoethanolamine,alizapride, azasetron, benzquinamide, bietanautine, bromopride,buclizine, clebopride, cyclizine, dimenhydrinate, diphenidol,dolasetron, meclizine, methallatal, metopimazine, nabilone, oxyperndyl,pipamazine, scopolamine, sulpiride, tetrahydrocannabinols,thiethylperazine, thioproperazine, tropisetron, and mixtures thereof.

The Formula I compounds of the invention can be administered orformulated in combination with an antidepressant. Suitableantidepressants include, but are not limited to, binedaline, caroxazone,citalopram, dimethazan, fencamine, indalpine, indeloxazinehydrochloride, nefopam, nomifensine, oxitriptan, oxypertine, paroxetine,sertraline, thiazesim, trazodone, benmoxine, iproclozide, iproniazid,isocarboxazid, nialamide, octamoxin, phenelzine, cotinine, rolicyprine,rolipram, maprotiline, metralindole, mianserin, mirtazepine, adinazolam,amitriptyline, amitriptylinoxide, amoxapine, butriptyline, clomipramine,demexiptiline, desipramine, dibenzepin, dimetacrine, dothiepin, doxepin,fluacizine, imipramine, imipramine N-oxide, iprindole, lofepramine,melitracen, metapramine, nortriptyline, noxiptilin, opipramol,pizotyline, propizepine, protriptyline, quinupramine, tianeptine,trimipramine, adrafinil, benactyzine, bupropion, butacetin, dioxadrol,duloxetine, etoperidone, febarbamate, femoxetine, fenpentadiol,fluoxetine, fluvoxamine, hematoporphyrin, hypericin, levophacetoperane,medifoxamine, milnacipran, minaprine, moclobemide, nefazodone,oxaflozane, piberaline, prolintane, pyrisuccideanol, ritanserin,roxindole, rubidium chloride, sulpiride, tandospirone, thozalinone,tofenacin, toloxatone, tranylcypromine, L-tryptophan, venlafaxine,viloxazine, and zimeldine.

The Formula I compounds of the invention can be administered orformulated in combination with an antifungal agent. Suitable antifungalagents include but are not limited to amphotericin B, itraconazole,ketoconazole, fluconazole, intrathecal, flucytosine, miconazole,butoconazole, clotrimazole, nystatin, terconazole, tioconazole,ciclopirox, econazole, haloprogrin, naftifine, terbinafine,undecylenate, and griseofulvin.

The Formula I compounds of the invention can be administered orformulated in combination with an anti-inflammatory agent. Usefulanti-inflammatory agents include, but are not limited to, non-steroidalanti-inflammatory drugs such as salicylic acid, acetylsalicylic acid,methyl salicylate, diflunisal, salsalate, olsalazine, sulfasalazine,acetaminophen, indomethacin, sulindac, etodolac, mefenamic acid,meclofenamate sodium, tolmetin, ketorolac, dichlofenac, ibuprofen,naproxen, naproxen sodium, fenoprofen, ketoprofen, flurbinprofen,oxaprozin, piroxicam, meloxicam, ampiroxicam, droxicam, pivoxicam,tenoxicam, nabumetome, phenylbutazone, oxyphenbutazone, antipyrine,aminopyrine, apazone and nimesulide; leukotriene antagonists including,but not limited to, zileuton, aurothioglucose, gold sodium thiomalateand auranofin; steroids including, but not limited to, alclometasonediproprionate, amcinonide, beclomethasone dipropionate, betametasone,betamethasone benzoate, betamethasone diproprionate, betamethasonesodium phosphate, betamethasone valerate, clobetasol proprionate,clocortolone pivalate, hydrocortisone, hydrocortisone derivatives,desonide, desoximatasone, dexamethasone, flunisolide, flucoxinolide,flurandrenolide, halcinocide, medrysone, methylprednisolone,methprednisolone acetate, methylprednisolone sodium succinate,mometasone furoate, paramethasone acetate, prednisolone, prednisoloneacetate, prednisolone sodium phosphate, prednisolone tebuatate,prednisone, triamcinolone, triamcinolone acetonide, triamcinolonediacetate, and triamcinolone hexacetonide; and other anti-inflammatoryagents including, but not limited to, methotrexate, colchicine,allopurinol, probenecid, sulfinpyrazone and benzbromarone.

The Formula I compounds of the invention can be administered orformulated in combination with another antiviral agent. Useful antiviralagents include, but are not limited to, protease inhibitors, nucleosidereverse transcriptase inhibitors, non-nucleoside reverse transcriptaseinhibitors and nucleoside analogs. The antiviral agents include but arenot limited to zidovudine, acyclovir, gangcyclovir, vidarabine,idoxuridine, trifluridine, levovirin, viramidine, ribavirin, andtaribavirin, as well as foscarnet, amantadine, rimantadine, saquinavir,indinavir, amprenavir, lopinavir, ritonavir, the α-interferons,β-interferons, adefovir, clevadine, entecavir, pleconaril, BMS-824393,and GI-5005.

The Formula I compounds of the invention can be administered orformulated in combination with an immunomodulatory agent.Immunomodulatory agents include, but are not limited to, methothrexate,leflunomide, cyclophosphamide, cyclosporine A, mycophenolate mofetil,rapamycin (sirolimus), mizoribine, deoxyspergualin, brequinar,malononitriloamindes (e.g., leflunamide), T cell receptor modulators,and cytokine receptor modulators, peptide mimetics, and antibodies(e.g., human, humanized, chimeric, monoclonal, polyclonal, Fvs, ScFvs,Fab or F(ab)₂ fragments or epitope binding fragments), nucleic acidmolecules (e.g., antisense nucleic acid molecules and triple helices),small molecules, organic compounds, and inorganic compounds. Examples ofT cell receptor modulators include, but are not limited to, anti-T cellreceptor antibodies (e.g., anti-CD4 antibodies (e.g., cM-T412(Boehringer), IDEC-CE9.1® (IDEC and SKB), mAB 4162W94, Orthoclone andOKTcdr4a (Janssen-Cilag)), anti-CD3 antibodies (e.g., Nuvion (ProductDesign Labs), OKT3 (Johnson & Johnson), or Rituxan (IDEC)), anti-CD5antibodies (e.g., an anti-CD5 ricin-linked immunoconjugate), anti-CD7antibodies (e.g., CHH-380 (Novartis)), anti-CD8 antibodies, anti-CD40ligand monoclonal antibodies (e.g., IDEC-131 (IDEC)), anti-CD52antibodies (e.g., CAMPATH 1H (Ilex)), anti-CD2 antibodies, anti-CD11aantibodies (e.g., Xanelim (Genentech)), anti-B7 antibodies (e.g.,IDEC-114 (IDEC)), CTLA4-immunoglobulin, and toll-like receptor (TLR)modulators (e.g., ANA773, IMO-2125, PF-04878691). Examples of cytokinereceptor modulators include, but are not limited to, soluble cytokinereceptors (e.g., the extracellular domain of a TNF-α receptor or afragment thereof, the extracellular domain of an IL-1β receptor or afragment thereof, and the extracellular domain of an IL-6 receptor or afragment thereof), cytokines or fragments thereof (e.g., interleukin(IL)-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12,IL-15, TNF-α, interferon (IFN)-α, IFN-β, IFN-γ, and GM-CSF),anti-cytokine receptor antibodies (e.g., anti-IFN receptor antibodies,anti-IL-2 receptor antibodies (e.g., Zenapax (Protein Design Labs)),anti-IL-4 receptor antibodies, anti-IL-6 receptor antibodies, anti-IL-10receptor antibodies, and anti-IL-12 receptor antibodies), anti-cytokineantibodies (e.g., anti-IFN antibodies, anti-TNF-a antibodies, anti-IL-13antibodies, anti-IL-6 antibodies, anti-IL-8 antibodies (e.g., ABX-IL-8(Abgenix)), and anti-IL-12 antibodies).

The Formula I compounds of the invention can be administered orformulated in combination with an agent which inhibits viral enzymes,including but not limited to inhibitors of HCV protease, such as VX-500,VBY-376, BMS-650032, MK-7009 (vaniprevir), TMC-435350, BI-201335,SCH-503034 (boceprevir), ITMN-191 (danoprevir), VX-950 (telaprevir),SCH900518 (narlaprevir), VX-813, VX-985, PHX1766, ABT-450, ACH-1625,ACH-1095, IDX136, IDX316, and ITMN-5489; inhibitors of NS5B polymerasesuch as GS-9190, MK-3281, VCH-759 (VX-759), VCH-916, ABT-333,BMS-791325, PF-00868554 (filibuvir), IDX-184, R7128, PSI-6130, R1626,PSI-7851, VCH-222 (VX-222), ABT-072, and BI207127; and inhibitors of theNS5A protein, such as BMS-790052, A-831, and AZD2836.

The Formula I compounds of the invention can be administered orformulated in combination with an agent which inhibits HCV polymerasesuch as those described in Wu, Curr Drug Targets Infect Disord. 2003,3(3), 207-19 or in combination with compounds that inhibit the helicasefunction of the virus such as those described in Bretner M, et al.Nucleosides Nucleotides Nucleic Acids. 2003, 22(5-8), 1531, or withinhibitors of other HCV specific targets such as those described inZhang X., IDrugs 2002, 5(2), 154-8.

The Formula I compounds of the invention can be administered orformulated in combination with an agent which inhibits viralreplication.

The Formula I compounds of the invention can be administered orformulated in combination with an agent which inhibits cyclophilins.Examples of cyclophilin inhibitors include, but are not limited to,Debio-025, NIM-811, and SCY-635.

The Formula I compounds of the invention can be administered orformulated in combination with cytokines. Examples of cytokines include,but are not limited to, interleukin-2 (IL-2), interleukin-3 (IL-3),interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6),interleukin-7 (IL-7), interleukin-9 (IL-9), interleukin-10 (IL-10),interleukin-12 (IL-12), interleukin 15 (IL-15), interleukin 18 (IL-18),platelet derived growth factor (PDGF), erythropoietin (Epo), epidermalgrowth factor (EGF), fibroblast growth factor (FGF), granulocytemacrophage stimulating factor (GM-CSF), granulocyte colony stimulatingfactor (G-CSF), macrophage colony stimulating factor (M-CSF), prolactin,and interferon (IFN), e.g., IFN-α, and IFN-γ).

The Formula I compounds of the invention can be administered orformulated in combination with hormones. Examples of hormones include,but are not limited to, luteinizing hormone releasing hormone (LHRH),growth hormone (GH), growth hormone releasing hormone, ACTH,somatostatin, somatotropin, somatomedin, parathyroid hormone,hypothalamic releasing factors, insulin, glucagon, enkephalins,vasopressin, calcitonin, heparin, low molecular weight heparins,heparinoids, synthetic and natural opioids, insulin thyroid stimulatinghormones, and endorphins.

The Formula I compounds of the invention can be administered orformulated in combination with β-interferons which include, but are notlimited to, interferon β3-1a, interferon β-1b.

The Formula I compounds of the invention can be administered orformulated in combination with α-interferons which include, but are notlimited to, interferon α-1, interferon α-2a (roferon), interferon α-2b,intron, Peg-Intron, Pegasys, consensus interferon (infergen) andalbuferon. The compounds of the invention can also be administered orformulated in combination with interferons such as BLX-883 (Locteron),Omega interferon, and PEG-Interferon lambda.

The Formula I compounds of the invention can be administered orformulated in combination with an absorption enhancer, particularlythose which target the lymphatic system, including, but not limited tosodium glycocholate; sodium caprate; N-lauryl-β-D-maltopyranoside; EDTA;mixed micelle; and those reported in Muranishi Crit. Rev. Ther. DrugCarrier Syst., 7, 1-33, which is hereby incorporated by reference in itsentirety. Other known absorption enhancers can also be used. Thus, theinvention also encompasses a pharmaceutical composition comprising oneor more Formula I compounds of the invention and one or more absorptionenhancers.

The Formula I compounds of the invention can be administered orformulated in combination with a cytochrome P450 monooxygenaseinhibitor, such as, but not limited to, ritonavir or a pharmaceuticallyacceptable salt, ester, and prodrug thereof to improve thepharmacokinetics (e.g., increased half-life, increased time to peakplasma concentration, increased blood levels) of a Formula I compoundthat is metabolized by cytochrome P450 monooxygenase. Thus, theinvention also encompasses a pharmaceutical composition comprisingFormula I compounds of the invention and one or more cytochrome P450monooxygenase inhibitors.

The Formula I compounds of the invention can be administered incombination with food to enhance absorption of the Formula I compoundsin the gastrointestinal tract and to increase the bioavailability of theFormula I compounds.

The Formula I compounds of the invention can be administered orformulated in combination with an alkylating agent. Examples ofalkylating agents include, but are not limited to nitrogen mustards,ethylenimines, methylmelamines, alkyl sulfonates, nitrosoureas,triazenes, mechlorethamine, cyclophosphamide, ifosfamide, melphalan,chlorambucil, hexamethylmelaine, thiotepa, busulfan, carmustine,streptozocin, dacarbazine and temozolomide.

The compounds of the invention and the other therapeutics agent can actadditively or, more preferably, synergistically. In one embodiment, acomposition comprising a compound of the invention is administeredconcurrently with the administration of another therapeutic agent, whichcan be part of the same composition or in a different composition fromthat comprising the compounds of the invention. In another embodiment, acompound of the invention is administered prior to or subsequent toadministration of another therapeutic agent. In a separate embodiment, acompound of the invention is administered to a patient who has notpreviously undergone or is not currently undergoing treatment withanother therapeutic agent, particularly an antiviral agent.

In one embodiment, the methods of the invention comprise theadministration of one or more Formula I compounds of the inventionwithout an additional therapeutic agent.

Pharmaceutical Compositions and Dosage Forms

Pharmaceutical compositions and single unit dosage forms comprising aFormula I compound of the invention, or a pharmaceutically acceptablesalt, or hydrate thereof, are also encompassed by the invention.Individual dosage forms of the invention may be suitable for oral,mucosal (including sublingual, buccal, rectal, nasal, or vaginal),parenteral (including subcutaneous, intramuscular, bolus injection,intraarterial, or intravenous), transdermal, or topical administration.Pharmaceutical compositions and dosage forms of the invention typicallyalso comprise one or more pharmaceutically acceptable excipients.Sterile dosage forms are also contemplated.

In an alternative embodiment, pharmaceutical composition encompassed bythis embodiment includes a Formula I compound of the invention, or apharmaceutically acceptable salt, or hydrate thereof, and at least oneadditional therapeutic agent. Examples of additional therapeutic agentsinclude, but are not limited to, those listed above.

The composition, shape, and type of dosage forms of the invention willtypically vary depending on their use. For example, a dosage form usedin the acute treatment of a disease or a related disease may containlarger amounts of one or more of the active ingredients it comprisesthan a dosage form used in the chronic treatment of the same disease.Similarly, a parenteral dosage form may contain smaller amounts of oneor more of the active ingredients it comprises than an oral dosage formused to treat the same disease or disorder. These and other ways inwhich specific dosage forms encompassed by this invention will vary fromone another will be readily apparent to those skilled in the art. See,e.g., Remington's Pharmaceutical Sciences, 18th ed., Mack Publishing,Easton Pa. (1990). Examples of dosage forms include, but are not limitedto: tablets; caplets; capsules, such as soft elastic gelatin capsules;cachets; troches; lozenges; dispersions; suppositories; ointments;cataplasms (poultices); pastes; powders; dressings; creams; plasters;solutions; patches; aerosols (e.g., nasal sprays or inhalers); gels;liquid dosage forms suitable for oral or mucosal administration to apatient, including suspensions (e.g., aqueous or non-aqueous liquidsuspensions, oil-in-water emulsions, or a water-in-oil liquidemulsions), solutions, and elixirs; liquid dosage forms suitable forparenteral administration to a patient; and sterile solids (e.g.,crystalline or amorphous solids) that can be reconstituted to provideliquid dosage forms suitable for parenteral administration to a patient.

Typical pharmaceutical compositions and dosage forms comprise one ormore carriers, excipients or diluents. Suitable excipients are wellknown to those skilled in the art of pharmacy, and non-limiting examplesof suitable excipients are provided herein. Whether a particularexcipient is suitable for incorporation into a pharmaceuticalcomposition or dosage form depends on a variety of factors well known inthe art including, but not limited to, the way in which the dosage formwill be administered to a patient. For example, oral dosage forms suchas tablets may contain excipients not suited for use in parenteraldosage forms. The suitability of a particular excipient may also dependon the specific active ingredients in the dosage form.

This invention further encompasses anhydrous pharmaceutical compositionsand dosage forms comprising active ingredients, since water canfacilitate the degradation of some compounds. For example, the additionof water (e.g., 5%) is widely accepted in the pharmaceutical arts as ameans of simulating long-term storage in order to determinecharacteristics such as shelf-life or the stability of formulations overtime. See, e.g., Carstensen, Drug Stability: Principles & Practice, 2d.Ed., Marcel Dekker, NY, N.Y., 1995, pp. 379-80. In effect, water andheat accelerate the decomposition of some compounds. Thus, the effect ofwater on a formulation can be of great significance since moistureand/or humidity are commonly encountered during manufacture, handling,packaging, storage, shipment, and use of formulations.

Anhydrous pharmaceutical compositions and dosage forms of the inventioncan be prepared using anhydrous or low moisture containing ingredientsand low moisture or low humidity conditions.

An anhydrous pharmaceutical composition should be prepared and storedsuch that its anhydrous nature is maintained. Accordingly, anhydrouscompositions are preferably packaged using materials known to preventexposure to water such that they can be included in suitable formularykits. Examples of suitable packaging include, but are not limited to,hermetically sealed foils, plastics, unit dose containers (e.g., vials),blister packs, and strip packs.

The invention further encompasses pharmaceutical compositions and dosageforms that comprise one or more compounds that reduce the rate by whichan active ingredient will decompose. Such compounds, which are referredto herein as “stabilizers,” include, but are not limited to,antioxidants such as ascorbic acid, pH buffers, or salt buffers.

Like the amounts and types of excipients, the amounts and specific typesof active ingredients in a dosage form may differ depending on factorssuch as, but not limited to, the route by which it is to be administeredto patients. However, typical dosage forms of the invention compriseFormula I compounds of the invention, or a pharmaceutically acceptablesalt or hydrate thereof comprise 0.1 mg to 1500 mg per unit to providedoses of about 0.01 to 200 mg/kg per day.

Oral Dosage Forms

Pharmaceutical compositions of the invention that are suitable for oraladministration can be presented as discrete dosage forms, such as, butare not limited to, tablets (e.g., chewable tablets), caplets, capsules,and liquids (e.g., flavored syrups). Such dosage forms containpredetermined amounts of active ingredients, and may be prepared bymethods of pharmacy well known to those skilled in the art. Seegenerally, Remington's Pharmaceutical Sciences, 18th ed., MackPublishing, Easton Pa. (1990).

Typical oral dosage forms of the invention are prepared by combining theactive ingredient(s) in an intimate admixture with at least oneexcipient according to conventional pharmaceutical compoundingtechniques. Excipients can take a wide variety of forms depending on theform of preparation desired for administration. For example, excipientssuitable for use in oral liquid or aerosol dosage forms include, but arenot limited to, water, glycols, oils, alcohols, flavoring agents,preservatives, and coloring agents. Examples of excipients suitable foruse in solid oral dosage forms (e.g., powders, tablets, capsules, andcaplets) include, but are not limited to, starches, sugars,micro-crystalline cellulose, diluents, granulating agents, lubricants,binders, and disintegrating agents.

Because of their ease of administration, tablets and capsules representthe most advantageous oral dosage unit forms, in which case solidexcipients are employed. If desired, tablets can be coated by standardaqueous or nonaqueous techniques. Such dosage forms can be prepared byany of the methods of pharmacy. In general, pharmaceutical compositionsand dosage forms are prepared by uniformly and intimately admixing theactive ingredients with liquid carriers, finely divided solid carriers,or both, and then shaping the product into the desired presentation ifnecessary.

For example, a tablet can be prepared by compression or molding.Compressed tablets can be prepared by compressing in a suitable machinethe active ingredients in a free-flowing form such as powder orgranules, optionally mixed with an excipient. Molded tablets can be madeby molding in a suitable machine a mixture of the powdered compoundmoistened with an inert liquid diluent.

Examples of excipients that can be used in oral dosage forms of theinvention include, but are not limited to, binders, fillers,disintegrants, and lubricants. Binders suitable for use inpharmaceutical compositions and dosage forms include, but are notlimited to, corn starch, potato starch, or other starches, gelatin,natural and synthetic gums such as acacia, sodium alginate, alginicacid, other alginates, powdered tragacanth, guar gum, cellulose and itsderivatives (e.g., ethyl cellulose, cellulose acetate, carboxymethylcellulose calcium, sodium carboxymethyl cellulose), polyvinylpyrrolidone, methyl cellulose, pre-gelatinized starch, hydroxypropylmethyl cellulose, (e.g., Nos. 2208, 2906, 2910), microcrystallinecellulose, and mixtures thereof.

Examples of fillers suitable for use in the pharmaceutical compositionsand dosage forms disclosed herein include, but are not limited to, talc,calcium carbonate (e.g., granules or powder), microcrystallinecellulose, powdered cellulose, dextrates, kaolin, mannitol, silicicacid, sorbitol, starch, pre-gelatinized starch, and mixtures thereof.The binder or filler in pharmaceutical compositions of the invention istypically present in from about 50 to about 99 weight percent of thepharmaceutical composition or dosage form.

Suitable forms of microcrystalline cellulose include, but are notlimited to, the materials sold as AVICEL-PH-101, AVICEL-PH-103 AVICELRC-581, AVICEL-PH-105 (available from FMC Corporation, American ViscoseDivision, Avicel Sales, Marcus Hook, Pa.), and mixtures thereof. Aspecific binder is a mixture of microcrystalline cellulose and sodiumcarboxymethyl cellulose sold as AVICEL RC-581. Suitable anhydrous or lowmoisture excipients or additives include AVICEL-PH-103™ and Starch 1500LM.

Disintegrants are used in the compositions of the invention to providetablets that disintegrate when exposed to an aqueous environment.Tablets that contain too much disintegrant may disintegrate in storage,while those that contain too little may not disintegrate at a desiredrate or under the desired conditions. Thus, a sufficient amount ofdisintegrant that is neither too much nor too little to detrimentallyalter the release of the active ingredients should be used to form solidoral dosage forms of the invention. The amount of disintegrant usedvaries based upon the type of formulation, and is readily discernible tothose of ordinary skill in the art. Typical pharmaceutical compositionscomprise from about 0.5 to about 15 weight percent of disintegrant,specifically from about 1 to about 5 weight percent of disintegrant.

Disintegrants that can be used in pharmaceutical compositions and dosageforms of the invention include, but are not limited to, agar-agar,alginic acid, calcium carbonate, microcrystalline cellulose,croscarmellose sodium, crospovidone, polacrilin potassium, sodium starchglycolate, potato or tapioca starch, pre-gelatinized starch, otherstarches, clays, other algins, other celluloses, gums, and mixturesthereof.

Lubricants that can be used in pharmaceutical compositions and dosageforms of the invention include, but are not limited to, calciumstearate, magnesium stearate, mineral oil, light mineral oil, glycerin,sorbitol, mannitol, polyethylene glycol, other glycols, stearic acid,sodium lauryl sulfate, talc, hydrogenated vegetable oil (e.g., peanutoil, cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil, andsoybean oil), zinc stearate, ethyl oleate, ethyl laureate, agar, andmixtures thereof. Additional lubricants include, for example, a syloidsilica gel (AEROSIL 200, manufactured by W.R. Grace Co. of Baltimore,Md.), a coagulated aerosol of synthetic silica (marketed by Degussa Co.of Plano, Tex.), CAB-O-SIL (a pyrogenic silicon dioxide product sold byCabot Co. of Boston, Mass.), and mixtures thereof. If used at all,lubricants are typically used in an amount of less than about 1 weightpercent of the pharmaceutical compositions or dosage forms into whichthey are incorporated.

Delayed Release Dosage Forms

Active ingredients of the invention can be administered by controlledrelease means or by delivery devices that are well known to those ofordinary skill in the art. Examples include, but are not limited to,those described in U.S. Pat. Nos. 3,845,770; 3,916,899; 3,536,809;3,598,123; and 4,008,719, 5,674,533, 5,059,595, 5,591,767, 5,120,548,5,073,543, 5,639,476, 5,354,556, and 5,733,566, each of which isincorporated herein by reference. Such dosage forms can be used toprovide slow or controlled-release of one or more active ingredientsusing, for example, hydropropylmethyl cellulose, other polymer matrices,gels, permeable membranes, osmotic systems, multilayer coatings,microparticles, liposomes, microspheres, or a combination thereof toprovide the desired release profile in varying proportions. Suitablecontrolled-release formulations known to those of ordinary skill in theart, including those described herein, can be readily selected for usewith the active ingredients of the invention. The invention thusencompasses single unit dosage forms suitable for oral administrationsuch as, but not limited to, tablets, capsules, gelcaps, and capletsthat are adapted for controlled-release.

All controlled-release pharmaceutical products have a common goal ofimproving drug therapy over that achieved by their non-controlledcounterparts. Ideally, the use of an optimally designedcontrolled-release preparation in medical treatment is characterized bya minimum of drug substance being employed to cure or control thecondition in a minimum amount of time. Advantages of controlled-releaseformulations include extended activity of the drug, reduced dosagefrequency, and increased patient compliance. In addition,controlled-release formulations can be used to affect the time of onsetof action or other characteristics, such as blood levels of the drug,and can thus affect the occurrence of side (e.g., adverse) effects.

Most controlled-release formulations are designed to initially releasean amount of drug (active ingredient) that promptly produces the desiredtherapeutic effect, and gradually and continually release of otheramounts of drug to maintain this level of therapeutic or prophylacticeffect over an extended period of time. In order to maintain thisconstant level of drug in the body, the drug must be released from thedosage form at a rate that will replace the amount of drug beingmetabolized and excreted from the body. Controlled-release of an activeingredient can be stimulated by various conditions including, but notlimited to, pH, temperature, enzymes, water, or other physiologicalconditions or compounds.

Parenteral Dosage Forms

Parenteral dosage forms can be administered to patients by variousroutes including, but not limited to, subcutaneous, intravenous(including bolus injection), intramuscular, and intraarterial. Becausetheir administration typically bypasses patients' natural defensesagainst contaminants, parenteral dosage forms are preferably sterile orcapable of being sterilized prior to administration to a patient.Examples of parenteral dosage forms include, but are not limited to,solutions ready for injection, dry and/or lyophylized products ready tobe dissolved or suspended in a pharmaceutically acceptable vehicle forinjection (reconstitutable powders), suspensions ready for injection,and emulsions.

Suitable vehicles that can be used to provide parenteral dosage forms ofthe invention are well known to those skilled in the art. Examplesinclude, but are not limited to: Water for Injection USP; aqueousvehicles such as, but not limited to, Sodium Chloride Injection,Ringer's Injection, Dextrose Injection, Dextrose and Sodium ChlorideInjection, and Lactated Ringer's Injection; water-miscible vehicles suchas, but not limited to, ethyl alcohol, polyethylene glycol, andpolypropylene glycol; and non-aqueous vehicles such as, but not limitedto, corn oil, cottonseed oil, peanut oil, sesame oil, ethyl oleate,isopropyl myristate, and benzyl benzoate.

Compounds that increase the solubility of one or more of the activeingredients disclosed herein can also be incorporated into theparenteral dosage forms of the invention.

Transdermal Dosage Forms

Transdermal dosage forms include “reservoir type” or “matrix type”patches, which can be applied to the skin and worn for a specific periodof time to permit the penetration of a desired amount of activeingredients.

Suitable excipients (e.g., carriers and diluents) and other materialsthat can be used to provide transdermal and topical dosage formsencompassed by this invention are well known to those skilled in thepharmaceutical arts, and depend on the particular tissue to which agiven pharmaceutical composition or dosage form will be applied. Withthat fact in mind, typical excipients include, but are not limited to,water, acetone, ethanol, ethylene glycol, propylene glycol,butane-1,3-diol, isopropyl myristate, isopropyl palmitate, mineral oil,and mixtures thereof.

Depending on the specific tissue to be treated, additional componentsmay be used prior to, in conjunction with, or subsequent to treatmentwith active ingredients of the invention. For example, penetrationenhancers can be used to assist in delivering the active ingredients tothe tissue. Suitable penetration enhancers include, but are not limitedto: acetone; various alcohols such as ethanol, oleyl, andtetrahydrofuryl; alkyl sulfoxides such as dimethyl sulfoxide; dimethylacetamide; dimethyl formamide; polyethylene glycol; pyrrolidones such aspolyvinylpyrrolidone; Kollidon grades (Povidone, Polyvidone); urea; andvarious water-soluble or insoluble sugar esters such as Tween 80(polysorbate 80) and Span 60 (sorbitan monostearate).

The pH of a pharmaceutical composition or dosage form, or of the tissueto which the pharmaceutical composition or dosage form is applied, mayalso be adjusted to improve delivery of one or more active ingredients.Similarly, the polarity of a solvent carrier, its ionic strength, ortonicity can be adjusted to improve delivery. Compounds such asstearates can also be added to pharmaceutical compositions or dosageforms to advantageously alter the hydrophilicity or lipophilicity of oneor more active ingredients so as to improve delivery. In this regard,stearates can serve as a lipid vehicle for the formulation, as anemulsifying agent or surfactant, and as a delivery-enhancing orpenetration-enhancing agent. Different salts, hydrates or solvates ofthe active ingredients can be used to further adjust the properties ofthe resulting composition.

Topical Dosage Forms

Topical dosage forms of the invention include, but are not limited to,creams, lotions, ointments, gels, solutions, emulsions, suspensions, orother forms known to one of skill in the art. See, e.g., Remington'sPharmaceutical Sciences, 18th eds., Mack Publishing, Easton Pa. (1990);and Introduction to Pharmaceutical Dosage Forms, 4th ed., Lea & Febiger,Philadelphia (1985).

Suitable excipients (e.g., carriers and diluents) and other materialsthat can be used to provide transdermal and topical dosage formsencompassed by this invention are well known to those skilled in thepharmaceutical arts, and depend on the particular tissue to which agiven pharmaceutical composition or dosage form will be applied. Withthat fact in mind, typical excipients include, but are not limited to,water, acetone, ethanol, ethylene glycol, propylene glycol,butane-1,3-diol, isopropyl myristate, isopropyl palmitate, mineral oil,and mixtures thereof.

Depending on the specific tissue to be treated, additional componentsmay be used prior to, in conjunction with, or subsequent to treatmentwith active ingredients of the invention. For example, penetrationenhancers can be used to assist in delivering the active ingredients tothe tissue. Suitable penetration enhancers include, but are not limitedto: acetone; various alcohols such as ethanol, oleyl, andtetrahydrofuryl; alkyl sulfoxides such as dimethyl sulfoxide; dimethylacetamide; dimethyl formamide; polyethylene glycol; pyrrolidones such aspolyvinylpyrrolidone; Kollidon grades (Povidone, Polyvidone); urea; andvarious water-soluble or insoluble sugar esters such as Tween 80(polysorbate 80) and Span 60 (sorbitan monostearate).

Mucosal Dosage Forms

Mucosal dosage forms of the invention include, but are not limited to,ophthalmic solutions, sprays and aerosols, or other forms known to oneof skill in the art. See, e.g., Remington's Pharmaceutical Sciences,18th eds., Mack Publishing, Easton Pa. (1990); and Introduction toPharmaceutical Dosage Forms, 4th ed., Lea & Febiger, Philadelphia(1985). Dosage forms suitable for treating mucosal tissues within theoral cavity can be formulated as mouthwashes or as oral gels. In oneembodiment, the aerosol comprises a carrier. In another embodiment, theaerosol is carrier free.

The Formula I compounds of the invention may also be administereddirectly to the lung by inhalation. For administration by inhalation, aFormula I compound can be conveniently delivered to the lung by a numberof different devices. For example, a Metered Dose Inhaler (“MDI”) whichutilizes canisters that contain a suitable low boiling propellant, e.g.,dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, carbon dioxide or other suitable gas can beused to deliver a Formula I compound directly to the lung. MDI devicesare available from a number of suppliers such as 3M Corporation,Aventis, Boehringer Ingelheim, Forest Laboratories, Glaxo-Wellcome,Schering Plough and Vectura.

Alternatively, a Dry Powder Inhaler (DPI) device can be used toadminister a Formula I compound to the lung (see, e.g., Raleigh et al.,Proc. Amer. Assoc. Cancer Research Annual Meeting, 1999, 40, 397, whichis herein incorporated by reference). DPI devices typically use amechanism such as a burst of gas to create a cloud of dry powder insidea container, which can then be inhaled by the patient. DPI devices arealso well known in the art and can be purchased from a number of vendorswhich include, for example, Fisons, Glaxo-Wellcome, Inhale TherapeuticSystems, ML Laboratories, Qdose and Vectura. A popular variation is themultiple dose DPI (“MDDPI”) system, which allows for the delivery ofmore than one therapeutic dose. MDDPI devices are available fromcompanies such as AstraZeneca, GlaxoWellcome, IVAX, Schering Plough,SkyePharma and Vectura. For example, capsules and cartridges of gelatinfor use in an inhaler or insufflator can be formulated containing apowder mix of the compound and a suitable powder base such as lactose orstarch for these systems.

Another type of device that can be used to deliver a Formula I compoundto the lung is a liquid spray device supplied, for example, by AradigmCorporation. Liquid spray systems use extremely small nozzle holes toaerosolize liquid drug formulations that can then be directly inhaledinto the lung.

In one embodiment, a nebulizer device is used to deliver a Formula Icompound to the lung. Nebulizers create aerosols from liquid drugformulations by using, for example, ultrasonic energy to form fineparticles that can be readily inhaled (See e.g., Verschoyle et al.,British J. Cancer, 1999, 80, Suppl 2, 96, which is herein incorporatedby reference). Examples of nebulizers include devices supplied bySheffield/Systemic Pulmonary Delivery Ltd. (See, Armer et al., U.S. Pat.No. 5,954,047; van der Linden et al., U.S. Pat. No. 5,950,619; van derLinden et al., U.S. Pat. No. 5,970,974, which are herein incorporated byreference), Aventis and Batelle Pulmonary Therapeutics.

In one embodiment, an electrohydrodynamic (“EHD”) aerosol device is usedto deliver Formula I compounds to the lung. EHD aerosol devices useelectrical energy to aerosolize liquid drug solutions or suspensions(see, e.g., Noakes et al., U.S. Pat. No. 4,765,539; Coffee, U.S. Pat.No., 4,962,885; Coffee, PCT Application, WO 94/12285; Coffee, PCTApplication, WO 94/14543; Coffee, PCT Application, WO 95/26234, Coffee,PCT Application, WO 95/26235, Coffee, PCT Application, WO 95/32807,which are herein incorporated by reference). The electrochemicalproperties of the Formula I compounds formulation may be importantparameters to optimize when delivering this drug to the lung with an EHDaerosol device and such optimization is routinely performed by one ofskill in the art. EHD aerosol devices may more efficiently deliverydrugs to the lung than existing pulmonary delivery technologies. Othermethods of intra-pulmonary delivery of Formula I compounds will be knownto the skilled artisan and are within the scope of the invention.

Liquid drug formulations suitable for use with nebulizers and liquidspray devices and EHD aerosol devices will typically include a Formula Icompound with a pharmaceutically acceptable carrier. Preferably, thepharmaceutically acceptable carrier is a liquid such as alcohol, water,polyethylene glycol or a perfluorocarbon. Optionally, another materialmay be added to alter the aerosol properties of the solution orsuspension of the Formula I compound. Preferably, this material isliquid such as an alcohol, glycol, polyglycol or a fatty acid. Othermethods of formulating liquid drug solutions or suspension suitable foruse in aerosol devices are known to those of skill in the art (see,e.g., Biesalski, U.S. Pat. Nos. 5,112,598; Biesalski, 5,556,611, whichare herein incorporated by reference) A Formula I compound can also beformulated in rectal or vaginal compositions such as suppositories orretention enemas, e.g., containing conventional suppository bases suchas cocoa butter or other glycerides.

In addition to the formulations described previously, a Formula Icompound can also be formulated as a depot preparation. Such long actingformulations can be administered by implantation (for examplesubcutaneously or intramuscularly) or by intramuscular injection. Thus,for example, the compounds can be formulated with suitable polymeric orhydrophobic materials (for example, as an emulsion in an acceptable oil)or ion exchange resins, or as sparingly soluble derivatives, forexample, as a sparingly soluble salt.

Alternatively, other pharmaceutical delivery systems can be employed.Liposomes and emulsions are well known examples of delivery vehiclesthat can be used to deliver Formula I compounds. Certain organicsolvents such as dimethylsulfoxide can also be employed, althoughusually at the cost of greater toxicity. A Formula I compound can alsobe delivered in a controlled release system. In one embodiment, a pumpcan be used (Sefton, CRC Crit. Ref Biomed Eng., 1987, 14, 201; Buchwaldet al., Surgery, 1980, 88, 507; Saudek et al., N. Engl. J. Med., 1989,321, 574). In another embodiment, polymeric materials can be used (seeMedical Applications of Controlled Release, Langer and Wise (eds.), CRCPres., Boca Raton, Fla. (1974); Controlled Drug Bioavailability, DrugProduct Design and Performance, Smolen and Ball (eds.), Wiley, New York(1984); Ranger and Peppas, J. Macromol. Sci. Rev. Macromol. Chem., 1983,23, 61; see also Levy et al., Science, 1985, 228, 190; During et al.,Ann. Neurol., 1989, 25, 351; Howard et al., J. Neurosurg., 71, 105(1989). In yet another embodiment, a controlled-release system can beplaced in proximity of the target of the compounds of the invention,e.g., the lung, thus requiring only a fraction of the systemic dose(see, e.g., Goodson, in Medical Applications of Controlled Release,supra, vol. 2, pp. 115 (1984)). Other controlled-release system can beused (see, e.g., Langer, Science, 1990, 249, 1527).

Suitable excipients (e.g., carriers and diluents) and other materialsthat can be used to provide mucosal dosage forms encompassed by thisinvention are well known to those skilled in the pharmaceutical arts,and depend on the particular site or method which a given pharmaceuticalcomposition or dosage form will be administered. With that fact in mind,typical excipients include, but are not limited to, water, ethanol,ethylene glycol, propylene glycol, butane-1,3-diol, isopropyl myristate,isopropyl palmitate, mineral oil, and mixtures thereof, which arenon-toxic and pharmaceutically acceptable. Examples of such additionalingredients are well known in the art. See, e.g, Remington'sPharmaceutical Sciences, 18th eds., Mack Publishing, Easton Pa. (1990).

The pH of a pharmaceutical composition or dosage form, or of the tissueto which the pharmaceutical composition or dosage form is applied, canalso be adjusted to improve delivery of one or more active ingredients.Similarly, the polarity of a solvent carrier, its ionic strength, ortonicity can be adjusted to improve delivery. Compounds such asstearates can also be added to pharmaceutical compositions or dosageforms to advantageously alter the hydrophilicity or lipophilicity of oneor more active ingredients so as to improve delivery. In this regard,stearates can serve as a lipid vehicle for the formulation, as anemulsifying agent or surfactant, and as a delivery-enhancing orpenetration-enhancing agent. Different salts, hydrates or solvates ofthe active ingredients can be used to further adjust the properties ofthe resulting composition.

Kits

The invention provides a pharmaceutical pack or kit comprising one ormore containers comprising a Formula I compound useful for the treatmentor prevention of a Hepatitis C virus infection. In other embodiments,the invention provides a pharmaceutical pack or kit comprising one ormore containers comprising a Formula I compound useful for the treatmentor prevention of a Hepatitis C virus infection and one or morecontainers comprising an additional therapeutic agent, including but notlimited to those listed above, in particular an antiviral agent, aninterferon, an agent which inhibits viral enzymes, or an agent whichinhibits viral replication, preferably the additional therapeutic agentis HCV specific or demonstrates anti-HCV activity.

The invention also provides a pharmaceutical pack or kit comprising oneor more containers comprising one or more of the ingredients of thepharmaceutical compositions of the invention. Optionally associated withsuch container(s) can be a notice in the form prescribed by agovernmental agency regulating the manufacture, use or sale ofpharmaceuticals or biological products, which notice reflects approvalby the agency of manufacture, use or sale for human administration.

The inventive agents may be prepared using the reaction routes andsynthesis schemes as described below, employing the general techniquesknown in the art using starting materials that are readily available.The synthesis of non-exemplified compounds according to the inventionmay be successfully performed by modifications apparent to those skilledin the art, e.g., by appropriately protecting interfering groups, bychanging to other suitable reagents known in the art, or by makingroutine modifications of reaction conditions. Alternatively, otherreactions disclosed herein or generally known in the art will berecognized as having applicability for preparing other compounds of theinvention.

Preparation of Compounds

The following Schemes 1-4 provide general procedures that can be used toprepare the deuterated 5,6-dihydro-1H-pyridin-2-one compounds of FormulaI.

As shown in Scheme 1, a cis 3-amino-bicyclo[2.2.1]heptane-2-carboxylicacid ester (US 2010/0034773A1 and PCT WO2008/124450A1) can betransformed to the deuterium labeled3-(4-fluoro-benzylamino)-bicyclo[2.2.1]heptane-2-carboxylic acid esterfrom corresponding 1-[halo(²H₂)methyl]-4-fluorobenzene or1[halo(²H₂)methyl]-4-fluoro-(²H₄)benzene, which can then be converted tothe final product by amide formation with(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid (US 2010/0034773A1 and PCT WO2008/124450A1) and cyclization.

An alternative to preparing deuterium labeledN-{3-[3-(4-fluoro-benzyl)-6-hydroxy-4-oxo-3-aza-tricyclo[6.2.1.0^(2,7)]undec-5-en-5-yl]-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-7-yl}-methanesulfonamidescan be accomplished via reductive amination of the starting cis3-amino-bicyclo[2.2.1]heptane-2-carboxylic acid ester and[4-fluorophenyl](2H) formaldehyde or [4-fluoro(²H₂)phenyl](²H)formaldehyde with sodium cyanoborodeuteride (Scheme 2). The deuteriumlabeled 3-(4-fluoro-benzylamino)-bicyclo[2.2.1]heptane-2-carboxylic acidesters can be converted to the final products with(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid as described in Scheme 1.

In another typical synthetic route (Scheme 3), an unsaturated cis3-amino-bicyclo[2.2.1]hept-5-ene-2-carboxylic acid ester (US2010/0034773A1 and PCT WO2008/124450A1) can be reduced and deprotectedunder catalytic conditions with deuterium. Under the appropriatereductive amination conditions, the cis3-amino-(5,6-²H₂)-bicyclo[2.2.1]heptane-2-carboxylic acid ester cansubsequently be converted to an N-benzyl amino ester. The deuteriumlabeled 3-(4-fluoro-benzylamino)-bicyclo[2.2.1]heptane-2-carboxylic acidesters can be converted to the final products with(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid as described in Scheme 1.

To incorporate deuterium into7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid a synthetic procedure shown in Scheme 4 can be employed.2-Amino-5-(²H₃)methanesulfonylamino-benzenesulfonamide can be preparefrom 2,5-diaminobenzenesulfonamide (US 2010/0034773A1 and PCTWO2008/124450A1) and methane-²H₃-sulfonyl chloride under standardsulfonylamino forming conditions.2-Amino-5-(²H₃)methanesulfonylamino-benzenesulfonamide can then betransformed into7-(²H₃)methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid following synthetic steps for the corresponding unlabeled7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid outlined in US 2010/0034773A1 and the PCT WO2008/124450A1. Usingthe amide formation and cyclization conditions described in Schemes1-3,7-(²H₃)methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ⁶-benzo[1,2,4]thiadiazin-3-yl)-aceticacid can further be transformed into the final products.

It is to be understood that the foregoing description is exemplary andexplanatory in nature, and is intended to illustrate the invention andits preferred embodiments. Through routine experimentation, the artisanwill recognize apparent modifications and variations that may be madewithout departing from the spirit of the invention.

1. A compound of Formula I

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶,R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², and R²³ are independently selected fromhydrogen and deuterium, and R⁹ is F, wherein at least one of R¹, R², R³,R⁴, R⁵, R⁶, R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹,R²⁰, R²¹, R²², and R²³ is deuterium, or a pharmaceutically acceptablesalt, hydrate, solvate, tautomer or stereoisomer thereof.
 2. Thecompound of claim 1 wherein at least one of the R², R³, or R⁴substituents is deuterium, wherein the remaining R substituents arehydrogen.
 3. The compound of claim 1 wherein at least one of the R¹² orR¹³ substituents is deuterium, wherein the remaining R substituents arehydrogen.
 4. The compound of claim 1 wherein at least one of the R⁷, R⁸,R¹⁰, R¹¹, R¹², R¹³ substituents is deuterium, wherein the remaining Rsubstituents are hydrogen.
 5. The compound of claim 1 wherein R¹⁶ or R¹⁷is deuterium and R¹⁸ or R¹⁹ is deuterium, wherein the remaining Rsubstituents are hydrogen.
 6. The compound of claim 1 wherein at leastone of R⁷, R⁸, R¹⁰, R¹¹, R¹⁶ or R¹⁷ is deuterium and R¹⁸ or R¹⁹ isdeuterium, wherein the remaining R substituents are hydrogen.
 7. Thecompound of claim 1 wherein at least one of R¹², R¹³, R¹⁶ or R¹⁷ isdeuterium and R¹⁸ or R¹⁹ is deuterium, wherein the remaining Rsubstituents are hydrogen.
 8. The compound of claim 1 wherein at leastone of R⁷, R⁸, R¹⁰, R¹¹, R¹², R¹³, R¹⁶ or R¹⁷ is deuterium and R¹⁸ orR¹⁹ is deuterium, wherein the remaining R substituents are hydrogen. 9.The compound of claim 1 wherein at least one of R², R³, R⁴, R¹² and R¹³substituents are deuterium, wherein the remaining R substituents arehydrogen.
 10. The compound of claim 1 wherein at least one of R², R³,R⁴, R⁷, R⁸, R¹⁰, R¹¹, R¹² and R¹³ substituents are deuterium, whereinthe remaining R substituents are hydrogen.
 11. The compound of claim 1wherein at least one of R², R³, R⁴, R¹⁶ or R¹⁷ is deuterium and R¹⁸ orR¹⁹ is deuterium, wherein the remaining R substituents are hydrogen. 12.The compound of claim 1 wherein at least one of R², R³, R⁴, R⁷, R⁸, R¹⁰,R¹¹, R¹², R¹³, R¹⁶ or R¹⁷ is deuterium and R¹⁸ or R¹⁹ is deuterium,wherein the remaining R substituents are hydrogen.
 13. A method fortreating or preventing hepatitis C virus infection in a mammal in needthereof, comprising administering to the patient a therapeuticallyeffective amount of a Formula I compound according to claim
 1. 14. Themethod of claim 13 further comprising one or more additional therapeuticagents.
 15. The method of claim 14 wherein one of the therapeutic agentsis an antiviral agent or an immunomodulatory agent.
 16. A method fortreating or preventing hepatitis C virus infection in a patient in needthereof, comprising administering to the patient a therapeuticallyeffective amount of a compound of Formula I according to claim 1 and apharmaceutically acceptable excipient, carrier, or vehicle.